Characterization of a fish antimicrobial peptide: gene expression, subcellular localization, and spectrum of activity.

摘要: Antimicrobial peptides are proposed to act as the first line of mucosal host defense by exerting broad-spectrum microbicidal activity against pathogenic microbes. Pleurocidin, a new 25-residue linear antimicrobial peptide, was recently isolated from skin secretions winter flounder (Pleuronectes americanus). The present study identifies cDNA and gene encoding pleurocidin. pleurocidin comprises four exons. Its upstream region demonstrates consensus binding sequences for transcription factors found in genes mammals, including identical NF-IL6 alpha gamma interferon response elements. Pleurocidin is predicted exist 68-residue prepropeptide that undergoes proteolytic cleavage its amino-terminal signal carboxy-terminal anionic propiece form active, mature peptide. Transmission electron microscopy localized mucin granules intestinal goblet cells. Significant synergy shown occur between D-cycloserine targeting Mycobacterium smegmatis. functionally active at physiologic concentrations magnesium calcium; however, high these divalent cations ablated pleurocidin's standard test strain, Escherichia coli D31. tested bacterial fungal clinical isolates showed activity. Together, data support hypothesis participates innate immunity, it may prove be beneficial therapeutic agent.